Conventional shakers used for vibration testing are limited in their ability to effectively apply a wide range of vibration frequencies to test objects of different masses. For effective vibration testing, the shaker must produce an output vibration force that is suitably proportional to the mass of the test object. As an example, conventional hydraulic shakers are generally not capable of generating vibration at relatively high frequencies (e.g., greater than about 300 Hz). On the other hand, conventional electro dynamic shakers are technically capable of generating sufficiently high output force at relatively high frequencies, but with attendant high electrical power consumption and associated expense. Conventional piezo-electric (PE) actuators are capable of producing sufficiently high output force at relatively high vibration frequencies, but have limited ability to generate that same level of force at relatively low vibration frequencies (e.g., less than about 200 Hz).
It is desirable in view of the foregoing to provide for application of high output vibration forces across a range of vibration frequencies that is wider than permitted by conventional technology.